remember, the original idea four years ago, president obama's promise was comprehensive reform. now, they're trying to get it done in the second term. mara. >> tracie potts, thanks for that. >>> we're learning more about that gefs stating fire that swept through a brazilian nightclub killed 233 people. nbc's annabel roberts joins us with the latest. what is the latest on the investigation? >> reporter: good morning, mara. well, i understand that actually a fourth person has now been detained by police, held for questioning so that makes two co-owners of the nightclub.the head of security at that club and a band member. and really investigations are focusing on why the fire spread so quickly. it appears that a member of the band lit some kind of pyrotechnic that set fire to the ceiling that was covered in some very flammable insulation. and investigations are focusing on that, i've heard but i cannot confirm at this stage that the fire club's safety permit had actually expired last year and it was in the process of getting that permit renewed. obviously, a lot of questions to be